Combined sprag and brake for power-driven vehicles



Nov. 24, 9 1,562,795

H. SAUVEUR OMBINED SPRAG AND BRAKE FOR POWER DRIVEN VEHICLES Filed Feb. 14. 1924 Figure 3,

Patented Nov. 24, 1925.

UNITED STA'FES PATENT OFFICE.

HARRY SAUVEUR, OF BERLIN-LANKWITZ, GERMANY, ASSIGNOR TO HANDEL-MAAT- SCHA'PPIJ H. ALBERT .DE BABY & 00., OF AMSTERDAM, NETHERLANDS.

COMBINED SPRAG AND BRAKE FOR POWER-DRIVEN VEHICLES.

Application filed February 14, 1924.

To all whom it may concern:

Be it known that I, HARRY SAUVEUR, a citizen of the German Republic, residing at 8 Franzstrasse, Berlin-Lankwitz, Germany, have invented certain new and useful Improvements in a Combined Sprag and Brake for Power-Driven Vehicles, of which the following is a specification.

The subject of this invention is a device constituting a combined sprag and brake for power-driven road vehicles as distinguished from railway vehicles in which device, in addition to the known function of the sprag, that is, to prevent the vehicle from running down-hill when the engine stops, the device in accordance with this invention can be used as an emergency brake, being operated by compressed air, and being independent of friction between the wheels and the road.

The purposes and advantages of this invention will appear more fully from the following description, having reference to the accompanying drawings, in which Figure 1 illustrates diagrammatically a device embodying the invention with the sprag in its raised or inoperative position.

Figure 2 represents the same device in one operative position? Figure 3 represents the same device in another operative position.

Figure 4': illustrates a modification hereinafter mentioned.

Figure 5 is an elevation of the device shown in Figure 1, viewed from the rear, that is, from the left hand side of the drawing, Figure 1.

Figure 6 is an enlarged detail view of the spur looking toward the right of Figure 1.

A indicates a portion of the framework of the vehicle, to which the sprag 1 is pivoted at a. In the example illustrated in Figures 1 to 3 the sprag is also secured to the framework by a chain or other flexible connection 0 A cylinder B is pivotally connected at 7 with the framework A, a piston 6 works in this cylinder, and a spring 5 tends to hold this piston in the position shown in Figure 1. A pipe 8 supplies compressed air to this cylinder when required. A hollow spur 3 is pivoted at 2 on the sprag 1., and is provided with a catch or cross bar -tt adapted to engage the sprag when the spur is turned into the position. shown in Serial No. 692,810.

Assuming the vehicle proceeding up an incline in the direction indicated by the ar row D in Figure 3 to come to a standstill, the vehicle then tends to run back in the direction of the arrow C, Figure 2. Compressed air from the pipe 8 is allowed to enter the cylinder B and overcomes the resistance of the spring 5, when the piston 6 will cause the sprag 1 to be lowered into the position shown in Figure 2, with its point bearing on the road. As soon as the vehicle begins to run backwards the spur 3 will thus be turned over into the inoperative position shown in Figure 2, but the sprag is pressed into the road by the power of the compressed air. When the vehicle moving 1n the direction of the arrow 'D is descending a hill, and it is required to use this device as an emergency brake, compressed air is admitted to the cylinder B, the point of the sprag 1 and the long arm of the spur 3 simultaneously engage the road, but while the sprag merely trails, the leading point of the spur 3 bores into the road, and the resistance of the road causes the spur to turn clockwise (viewing Figure 3) about its pivot 2, until the catch or cross-bar 4 reaches and slightly lifts the sprag, when both points of the spur will bear on the road and exert a powerful braking action. The operative parts of the sprag and spur may be made with extended or shovel-like edges to increase their grip on the road.

In comparison with the known mechanically released sprags, which are liable to stick in their bearings owing to the accumulation of dirt or rust, the sprag operated by compressed air as above described can be rapidly lowered under all conditions, and also serves as an emergency brake, because if a sufficient piston area and sufficient air pressure be employed, the sprag or spur can.

be pressed with such force on or into the surface of the road as to brake the vehicle quite independently of brakes acting on the wheels; for instance, if in descending a frozen or other slippery road the wheels skid, the sprag can be caused to set up a braking action which is sufficient to bring the vehicle to a standstill.

The admission of compressed air to the pipe 8 can be effected by the usual drivers valve controlling the air brakes, which for this purpose may have a special position for ,voir-1 l, and with an air pipe 9 connected withthe motor vehicle. Two plstons and 16 of different sizes work in the cylinder 13, the. bore of which atthe part nearest the :front of the trailer vehicle is reduced so that .the smaller piston- 16 fits therein. The pres sure in the pipe 9 is normally continuous,

and holds the pistons forward so that the sprag 1 is kept in a raised-position. On the cessation of pressure in the pipe 9, whether caused bytheopening of; the drivers .valve .or bythe detachment of the trailer accidentally or =otherwise, as for example, on-the breakage of a coupling, the 2111' pressure to the right of the piston 15 displaces this p1ston to the left (referring to Figure 4), the

piston-16 participating :in this movement, so

that the air pressure in'the cylindeinlifi and auxiliary reservoir 14: is practically maintamed. The sprag 1 is by this movementof the p1stons, presseddown upon the road, and

acts either as a-sprag or abrake,.aocording to whether the vehicle is upon an ascending or-"descending, part not the road, precisely as, ;m the-case, ,ofthedevrce illustrated in Figures 1 to 3.

What I claim and desire. tosecu-re by Letvters Patent of the United States is 1. In a road vehicle'of theiclass described,

the combination of a pivoted sprag having apoint to engage the road surface, a twoarmed spur pivoted on said sprag, said sp-ur being adapted to act as a brake and to lift said sprag, a cylinder connected with a source of compressed air, and a piston movable in said cylinder, said piston being .operatively connected with said sprag.

2. In a road vehicle of the class described, the combination of a pivoted sprag having a point to engage the road surface, a twoa-rmed spur pivoted on said sprag, said spur having a cross-bar adapted to engage and lift said sprag and being adapted to act as a brake, a cylinder connected with a source of compressed air, and a piston movable in said cylinder, said piston being operatively connected with said sprag.

3. In a road vehicle oi the class described, the combination of a pointed sprag pivoted at oneend to the vehicle and connectedat its opposite endwith said vehicle by a flexible connection, a two-armed spur carried on said sprag and partly rotatable thereon, said spur being provided with a cross-bar adapt ed to engage said sprag to limit the movement of said spur, a fluid-pressure cylinder, and a piston movable in said cylinder and operatively connectedwith said sprag.

A combined spraggingand braking device for a power-driven road vehicle, comprising in. combination a pointed sprag pivoted at one end to the framework of the vehicle and connected at, its oppositeend with said framework by a flexible connection, a two-armed spur oarried onsaid sprag and partly rotatablecthereon, said spur having a cross-bar adapted toengage and lift said sprag, a fluid pressurecylinder, apiston movable in said cylinder. and operatively connected with saidsprag intermediate of its ends, a pipe to deliver compressed air at one v,sideof said piston to move said pistonin one direction, and a spring tending to move said piston in the, opposite direction.

, HARRY SAUVEUR. 

